Submounts for semiconductor light emitting devices and methods of forming packaged light emitting devices including dispensed encapsulants
View Patent ↗A submount for mounting an LED chip includes a substrate, a die attach pad configured to receive an LED chip on an upper surface of the substrate, a first meniscus control feature on the substrate surrounding the die attach pad and defining a first encapsulant region of the upper surface of the substrate, and a second meniscus control feature on the substrate surrounding the first encapsulant region and defining a second encapsulant region of the upper surface of the substrate. The first and second meniscus control features may be substantially coplanar with the die attach pad. A packaged LED includes a submount as described above and further includes an LED chip on the die attach pad, a first encapsulant on the substrate within the first encapsulant region, and a second encapsulant on the substrate within the second encapsulant region and covering the first encapsulant. Method embodiments are also disclosed.
1. A method of forming an LED submount, comprising:
providing a patterned metal layer on a substrate, the patterned metal layer including a die attach pad;
providing a meniscus control feature surrounding the die attach pad and defining an encapsulant region of the upper surface of the substrate configured to limit the flow of an encapsulant material out of the encapsulant region; and
providing an encapsulant flow limiting feature within the encapsulant region, the surface feature configured to slow a flow of encapsulant material through the encapsulant region.
2. The method of claim 1 , further comprising providing a meniscus extension feature within encapsulant region, the meniscus extension feature surrounding the die attach pad.
3. The method of claim 2 , wherein the meniscus extension feature has a peripheral shape that is different from a peripheral shape of the meniscus control feature.
4. The method of claim 1 , wherein the encapsulant material comprises a wavelength conversion material.
5. The method of claim 1 , wherein the die attach pad and the meniscus control feature comprise a same material.
6. The method of claim 5 , wherein the die attach pad and the meniscus control feature comprise a metal film.
7. The method of claim 5 , wherein the die attach pad and the meniscus control feature comprise a polymer film.
8. The method of claim 5 , wherein the encapsulant flow limiting feature comprises the same material as the die attach pad and the meniscus control feature.
9. The method of claim 1 , wherein the encapsulant flow limiting feature comprises a plurality of spaced apart surface features on the upper surface of the substrate.
10. A method of forming a packaged LED, comprising:
depositing a film on a substrate;
patterning the film to form a die attach pad;
providing a meniscus control feature surrounding the die attach pad and defining an encapsulant region of the upper surface of the substrate configured to limit the flow of an encapsulant material out of the encapsulant region;
providing a surface feature within the encapsulant region, the surface feature configured to slow a flow of encapsulant material through the encapsulant region;
mounting an LED chip on the die attach pad;
dispensing an encapsulant material on the substrate and the LED chip within the encapsulant region; and
curing the encapsulant material.
11. The method of claim 10 , wherein patterning the film comprises patterning the film to form a wirebond pad within the encapsulant region, the method further comprising forming a wirebond connection between the LED chip and the wirebond pad.
12. The method of claim 10 , further comprising pre-dispensing a quantity of encapsulant material adjacent the LED chip prior to dispensing the first encapsulant material.
13. The method of claim 10 , wherein the encapsulant material comprises a wavelength conversion material.
14. The method of claim 10 , further comprising providing a meniscus extension feature within encapsulant region, the meniscus extension feature surrounding the die attach pad.
15. The method of claim 14 , wherein the meniscus extension feature has a peripheral shape that is different from a peripheral shape of the meniscus control feature.
16. The method of claim 10 , wherein the die attach pad and the meniscus control feature comprise a same material.
17. The method of claim 16 , wherein the die attach pad and the meniscus control feature comprise a metal film.
18. The method of claim 16 , wherein the die attach pad and the meniscus control feature comprise a polymer film.
19. The method of claim 16 , wherein the encapsulant flow limiting feature comprises the same material as the die attach pad and the meniscus control feature.